i think i got a virus recently, as files i dowloaded and shared were contaminated. I tried to install norton antivirus 2003 but it gave an error message, something like
" you don't have the right to install, conctact your system adminstrator.."

But i am the system administrator.
I have win xp pro and i tried to look in the control panel and software installation restriction but could'nt find any problem.